Preparation And Properties Of Non-isocyanate Polyurethane Based On Cardanol

This article combined the natural product cashew phenol extracted from the cashew shell oil with the cyclophosphonitrile,then the greenhouse gas CO₂ was immobilized in the structure.A series of bio-based non-isocyanate polyurethane NIPUs were prepared by the reaction of cyclic carbonate and amino group.The mechanical properties,surface properties,thermal properties and solvent swelling properties of these materials were studied.Firstly,six-arm-branched cyclophosphonitrile EHCPP1-6,EHCPP2-6 and EHCPP3-6 with different epoxy values were synthesized from six-arm-branched cashew phenolic cyclophosphonitrile HCPP by the epoxidation reaction with metachloroperbenzoic acid system.Cyclic carbonate was synthesized by fixing carbon dioxide on EHCPP to form the corresponding carbonated bio-based intermediates CHCPP1-6,CHCPP2-6 and CHCPP3-6.And then the three-step method was used to synthesize three kinds of biological based diamines FA-a,FA-b and FA-c as small molecular curing agent.A series of NIPUs products were synthesized by thermal curing of cashew phenolic cyclocarbonate and furfural-based diamine.All the compounds were characterized by NMR and FT-IR,and the curing conditions were investigated by FT-IR and gel content testing.The study of the properties of NIPUs showed that the gel content increased alone with the solubility of three kinds of diamine curing agents FA-a,FA-b and FA-c in CHCPP,the lowest gel content was 77.8% of PU1-6a,the highest was 97.3% of PU3-6c.And all of the NIPUs were surface hydrophobic.The maximum elongation at break was 41.29% of PU1-6a and the lowest was 7.77% of PU3-6c.On the contrary,corresponding elastic modulus were 0.13 MPa and 380.22 MPa which increased alone with the gel contents.The lowest glass state temperature was 6.1? and the highest was 60.5?.The initial decomposition temperatures T5% were concentrated in the range of 248.8-276.8?,and the maximum decomposition rate temperatures Tmax1 and Tmax2 were 295.7-344.5? and 427.0-448.1?,respectively.The theoretical limit oxygen indexes of the 9 kinds of NIPUs were within the range of 22-27.The water-swelling properties and the toluene-swelling properties of materials decreased alone with the increase of the gel contents,and the ranges finally reached 2.1%-19.1% and 40.3%-149% after 15 d.The water absorbability increased slowly,and the absorption of toluene increased first and then decreases until reached fixed values.